It seems now that the fourth fundamental circuit element - referred to as the "memristor" - cannot exist in physical reality. In principle, no realistic physical model can be proposed for a solid state memory device which would operate in accordance with Chua's mathematical concept of genuine non-volatile memristors/memristive systems. When analyzed under physical aspects, the hypothetical mathematical state equations defining non-volatile memristors are by themselves in severe conflict with fundamentals of physics as discussed in "Fundamental Issues and Problems in the Realization of Memristors" by P. Meuffels and R. Soni (http://arxiv.org/abs/1207.7319) and "On the physical properties of memristive, memcapacitive, and meminductive systems" by M. Di Ventra and Y. V. Pershin (http://arxiv.org/abs/1302.7063).

The idea of a memory that is non-volatile, as fast as DRAM (I doubt the claim it is faster, the address logic will dominate that) and smaller is great. It is nice to hear that is coming. Of course, they said the same thing for FRAM.
However, people keep hyping this idea that we can mimic the human brain. Let's be clear about this:
- We don't know how the brain works. We know how one component, the neuron works. We don't have more than a tiny clue as to how that combines to make the neural part of a brain. The impact of the thousands of neurotransmitters and non-neural cells from a processing point of view is unknown. How can we mimic something we don't understand?
- We can't control an artificial brain, any more than we can control a human brain. How would you like to deal with a psychopath that is 10 times smarter than you, and thinks 1000 times faster? Until we understand this we'd better keep our neural network experiments very small scale.

Memristors have been conceived much Earlier than 1971, where only the name has been changed from "Memistor" bei adding an "r" behind "Mem". Stanford-Professor Bernie Widrow has founded the "Memistor Corporation" already in the early sixties. However, the implementation technology of this early memistor could not follow Moore's law.

The R & D smoking around the "memristor" stuff seems to be continuing in the New Year. That's really funny, because - up to now - no one has been able to show that Chua's hypothetical concept of nonvolatile memristor/memristive systems can be realized, i.e., to propose a reasonable physical model that would satisfy the mathematical state equations of such a system.

Memristor is just a component, like resistor, inductor or capacitor...saying it mimics the brain stretches reality too much...overall an exciting research component but we have not seen any commercial application from HP yet, still waiting for the memristor revolution!